This application relates generally to air seeders used for planting agricultural crops and, more particularly, to the meter roller assemblies used in air seeders to meter the flow of seed and/or fertilizer into the flow or air and, more specifically, to segmented metering sections for use in such assemblies.
In modern large scale agricultural operations, seed and/or fertilizer are typically applied to the soil through a series of seed tubes which are associated with soil working tools across the width of a soil working machine. Typically a group of such tubes is fed seed or fertilizer by a distribution header. The distribution header is in turn fed from a tank which may be configured as a separate cart for towing in advance of or trailing the soil working implement.
A metering system is associated with the tank for distribution of product from the tank to the distribution headers of the seed tubes. The metering system normally includes a meter roller situated below the tank in a meter box assembly secured to the tank. Typically the meter box will have a series of outlets known as runs, each of which leads through intermediate tubing to one of the distribution headers. The total number of possible runs typically extends the length of the meter roller. Depending on the number of distribution headers on the soil working implement, the roller assembly will consist of fluted metering sections corresponding to runs which are operational and preferably a single blank roller spacer extending across the width of the runs which are not operational. Product is then delivered to distribution headers which are connected to the runs containing the fluted metering sections and no product is delivered from those runs which are, in effect, blanked off. Along with the metering sections and blank sections, the meter roller assembly may comprise various spacers, bearings, etc.
It is also typically the case that some distribution headers feed more runs than others, so that the amount of metered product to the headers will be required to be varied. Spacers, ring blanks, and the like have been used for this purpose.
Various problems have arisen in the use of known meter rollers. Typical such problems involve severe torque and tolerance problems, corrosion caused by leakage of product through gaps between segments; pulsing delivery of product to the headers; difficulties in delivering a large seed or large particle product to the headers at the proper rate; and difficulties in delivering very fine products to the headers at the desirable rate.
It is desirable to provide an improved meter roller assembly to address the problems enumerated above and others.
Various approaches have been used in the past to attempt to provide segmented meter rollers; that is, meter rollers in which metering sections are divided as between fluted or active segments, and blank, or inactive segments.
One such prior method varies the amount of product delivered by each fluted metering roller by fixing a varying number of thin rings about the center line of the roller to simply reduce the volume of product to be delivered by the roller. This was intended to compensate for the differing numbers of active seed or fertilizer delivery tubes emanating from the distribution header fed by that particular metering roller.
Another method used to reduce flow from a given run comprises reducing the width of the fluted metering section and inserting separate spacers on each side of the metering section. This method results in a very large number of parts in the segmented meter roll assembly with consequent severe tolerance and torque problems.
Of interest are Canadian Patents 1,289,013; and 1,149,235 and Canadian published application Serial No. 2,242,115.